So when does the YS 1.20 come out?

to laughingstill:

Exactly. It's all pretty silly.

Now if I only had a dime for every time someone said "Wow listen to that heli - it's got a lot of POWER." I could probably have another set of batts for my 6HV.

FYI measuring power isn't terribly difficult but you would need to build a motor stand which allows you to measure torque, a tach, a prop adapter and a bunch of props. You could do it on the cheap for $100 i'm sure. It's too much work just to measure a number which at the end of the day doesn't add anything to your heli experience.

Avant RCScorpion Power SystemsThunder Power RCKontronik Drives

Exactly.

Here's the rub - electric motors can have wildly different efficiencies.

So, let's take two different motors, Motor A and B

Motor A produces 3000W peaks through the ESC

Motor B produces 2500W peaks through the ESC

Which one makes more power?

The answer is.... we don't know from this info!

So let's say Motor A, under load, has a 70% efficiency and Motor B is 85% under load. Then we get:

Motor A output power = 2100W
Motor B output power = 2125W

In this case, I would hope I have Motor B in my heli.

But, in the world of internet forums, the bigger number wins. So, people with the Brand A motor will go online and say "hey i got 3000W out of mine!" while the Brand B folks will say "Hey i'm only getting 2500W - this motor sucks i'm switching to Brand A." Then they'll complain about their flights being a minute shorter but they don't really mind so much because the power is worth it.

I got a fever! The only prescription is MORE 6HV

I keep hearing about these 90Es putting out 10HP on 12s,can someone please direct me to a video.Thats twice + the power of my 90s and i feel i have adequate power

If this is true then its putting out more power than my 3W 100 ON A 35%

I just want to see some proof.I have seen some vids but i couldnt tell any difference in E power v/s Nitro.and has this proof been dyno tested or just assumption?

Heli papa - I hear you...I feel my T600 nitro also has plenty of power, but not as much abundance as does my 6S5000 Outrage 550 with an 1800 watt motor...more to the point, when I was at IRCHA 2010, I pitted near where Tim flew his "Beast" electric. It was freakin' scary how much insane power was being imparted on the air by those rotors. Holding crazy pitch without throttle management...just sick power loops that sounded scary. The biggest thing I see the 12S machines doing which shows me how much greater the power is, is the lack of bog or lag the main rotor has when in climbing manuevers. Watch Kyle Dahl's Logo 600, or anything similar. It rockets to altitude like it's not even there, faster than the 90 nitros.

Rob

Heli papa,

Regardless of the debates about calculating hp through math, the logger data for rpm really tells the story of the power these eletric models have.

For example, let's first take a 450 kV motor and gear it at between 9.7 and 10:1 on 12S. In this configuration, the system will not hold 2000 rpm under any kind of load. Next, I can raise the gearing to 9.3 or 9.5 and have the model easily have the power to pull 2000 rpm at 10D of pitch with only modest rpm drops under load. The system will pull about 4000 watts like this. From there we can continue to make the gearing taller and taller down into the mid or lower 8's of gearing while at the same time pulling pitch of 11-13D of pitch with little or no drop in headspeed. We can prove this on a logger. Unlike a glow engine, an eletric system will pull harder and harder the more you load it up to the limitations of the ESC, motor, and batteries. Of late we have 65C batteries and 120-160 NOMINAL ESC's that will deliver all the current for which the motor asks under nominal loading and will for the most part keep up for bursts of nearly twice nominal wattage. There is no way in hell even a 120 glow engine can do this. If anyone doubts this fact, then put an RPM sensor on an Eagletree and watch just how much the rpm drops under load. Guys claim how their nitro model will pull so and so much pitch at 2000 rpm. If "pull" means load a bit going straight up and keep going, then that's fine. If "pull" means holding the set rpm under pure collective and then even, for the most part, with cyclic thrown in on top, then you're going to be disappointed with what a logger tells you about the nitro engine. If the new 120 is a 5 hp motor with the right exhaust and 30%, that's great. But the most you're going to ever get out of is that 5hp. Load the electric harder, and it'll blow by 5 hp and just keep right on going for more than just a few seconds of burst.

A word, too, about this runtime thing that guys bring up. The 700 class electrics that will only go 4:30 are often geared to make 7000+ watts of power, and guys ask for it often in a flight because that much power under your left thumb is really fun. If you geared that same model to something more sensible, flight times would be remarkably more similar to a glow model making the same amount of power. I can get 6:45+ out of my 700 class model which is geared to peak around 4000W. If a nitro model were consistently peaking at 7+ hp over the course of a flight while roughly holding set rpm, I double damn guarantee anyone that the model would not run 8 or 9 minutes on only 20 ounces of glow fuel. You simply can't make that much power at our typical engine rpm with but so little fuel .

Peak Aircraft/Team Minicopter Team Futaba Team Kontronik USA

consistently delivering

That is THE phrase that gets confused and misinterpreted.

No argument that electrics have gobs of torque and unreal power (ie my eAurora), but the claims of 14+HP are only bursts of power. If you look at your logger, you aren't pulling 200+ amps consistently. That is how we are able to run 10 and 12ga wire on our batteries. If we were truly pulling the insane power consistently, we would literally be melting the wires.

The technology is gaining leaps and bounds. We are already to the point of having consistent power (my biggest gripe about electrics in the early days) during the flight, which we didn't have a handful of years ago.

As for Tim's Beast, it is unreal, but it will cause the ESC to cut out on demand even with the bundle of capacitors on the nose of the heli. To say he has that power available throughout the flight is not correct.

Not to be off topic, but is there a link to a photograph of his 14S Trex anywhere that I could look at?

Avant RCScorpion Power SystemsThunder Power RCKontronik Drives

I wish less time would be spent on trying so hard to match/compare to the performance of a 12S 700 class electric and more on focusing on getting the motor to run well, as smoothly as a 90, and with comparable bearing life. It's a pointless pissing match any other way because whatever weight or power figure to which you're comparing is going to be history in 6-12 months with the way electric technology is evolving and without any increase in all up model weight but with progressively increasing power and flight time.

Not to be off topic, but is there a link to a photograph of his 14S Trex anywhere that I could look at?

It's a 12S...2X 5000 6S TP 45C's. I saw him fly it at Brooks in June.
It cut out twice during the flight. He glided for a few seconds with a little head speed, and it kicked up again....I think he said he was running 2300 or 2350 HS.

But the most you're going to ever get out of is that 5hp. Load the electric harder, and it'll blow by 5 hp and just keep right on going.

This is a misleading statement. Just because the motor is drawing a given wattage does not mean it is turning that wattage into power. One you get so much current into a motor (or any coil for that matter) the EM field generated by each individual winding starts working more to push the coils apart than it does to turn the motor. Once you pass this point, you can draw all the extra power you want, all it will do is cook your motor.

By your logic, i should be able to plug any motor i like into 120 mains power via a compatible ESC to do the job, and it will pull my house down the block.

Electric motors have performance limits just as do IC engines. The critical difference in our hobby is that loading up an electric motor does not compromise its ability to make power, whereas bogging down an IC engine does.

If you want to have some numbers to brag about, take your electric motor and attach it to a dyno, the attach a comparable-size glow engine and compare the results. The wattage being pulled through the ESC is not the HP being put out by the motor. Saying that it is is the same as claiming that the BTU output of the fuel a nitro burns is the same as the HP that motor can put out.

AMA 700159

Ryan,

I agree with you. Point of clarification for what I was saying about Tim's model. I'm not saying it will allow him to pull that kind of power ongoing. The distinction is that the electric will allow him to ask for the power in increments over the course of the flight while maintaining something near his set rpm, while the nitro cannot produce that kind of peak while the headspeed is maintained. Hell, even if his average power was only 2/3 or less of his peak (still well over statistical majority), he'd likely be making well over 5hp and I doubt causing any component in the system to cut out or down regulate.

I shudder to think of the kind of power these models are going to be able to pull not just consistently (meaning repeated peaks over and over through the flight) but CONSTANTLY (which means just what it says) in months or just a year from now. Geeeeezzzzzzzzz...............

Shu,

I fully understand that the conversion of the power in the batteries is not completely efficient. If it were, we wouldn't have heat sinks on ESC's and have to watch the temps of the motors. An electric model will literally melt itself down and/or burn itself up trying to deliver what is asked of it and if that request is excessive. I usually qualify any statement I make about potential power from electric with the phrase "up to the limitations of the weakest link in the system".

When you've flown a 700 class electric, what has been your impression about the power disparity between it and a 91 sized nitro model you've also flown? My little corner of the world is flying AMA/F3C. When we went from glow (and I mean the finest 91 engines you could buy tuned to run as hard as they could except maybe for Scott Gray's whose run harder still) there was absolutely no comparison in power. You don't need a dyno to prove it; you can feel it when you're flying. That's why I said earlier that it was such a pissing match to debate the power of a nitro verus an electric within the airframes in question. Each propulsion system ought to have its own personal sandbox .

Insha Allah made in america

When you've flown a 700 class electric, what has been your impression about the power disparity between it and a 91 sized nitro model?

When we went from glow (and I mean the finest 91 engines you could buy tuned to run as hard as they could except maybe for Scott Gray's whose run harder still) there was absolutely no comparison in power. You don't need a dyno to prove it; you can feel it when you're flying. That's why I said earlier that it was such a pissing match to debate the power of a nitro verus an electric within the airframes in question. It ain't close to the same now, and going to a 120 is not going to make it a level field either.

When a person has PERSONALLY EPERIENCED the difference, it's hard not to post about it!!!